HEMITHYROIDECTOMY OR PARTIAL THYROIDECTOMY – THE PROCEDURE AND THE RISKS
Hemithyroidectomy or partial thyroidectomy involves removal of part of the thyroid gland, up to half, or an entire lobe. It usually performed for the diagnosis of atypical or potentially malignant thyroid nodules, nodular goitre affecting only one side of the gland, or thyrotoxicosis due to a single toxic adenoma. Partial or hemithyroidectomy is a straightforward procedure performed under general anaesthesia, with a supplemental local anaesthetic cervical plexus block to reduce post-operative pain and discomfort. An incision is required and this is best placed in a skin crease high in the neck in order to provide an optimal cosmetic outcome. A hospital stay of either one night is standard. After a partial or hemithyroidectomy thyroxine replacement fis usually not required although 10 to 20%bof pateints may not have sufficient thyroid reserve in the remaining lobe and may require a small dose of thyroxine as a supplement.
Any operation carries with it the risk of a complication or unanticipated outcome. General risks of any operation include the possibility of an anaesthetic reaction, bleeding, infection, or thrombosis. There are also clearly a significant number of exceedingly uncommon potential complications which cannot be detailed. The specific risks of total thyroidectomy include:
DAMAGE TO THE RECURRENT LARYNGEAL NERVES: The recurrent laryngeal nerves supply the muscles of the larynx which are responsible for the voice as well as for protecting the airway. These nerves run directly through the operative site and lie against the back of the thyroid gland. They are often stretched during removal of the thyroid and may be damaged, or may temporarily lose their function after surgery. Loss of function of one nerve leads to a croaky voice. The risk of this occurring in expert hands is 1% (1 in 100 operations) but may be higher with less experienced surgeons. Some surgeons use nerve monitoring although there is absolutely no evidence that this reduces the risk of nerve damage (see FAQ on IONM).
PERSISTENT DISEASE: At surgery every attempt is made to remove all of the thyroid tissue, however sometimes small embryological remnants may be left behind on the side removed and these can slowly grow to cause a recurrent goitre. The risk of this happening is around 2%.